From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v3 27/55] KVM: arm/arm64: vgic-new: Add PRIORITY registers handlers Date: Thu, 12 May 2016 10:10:33 +0100 Message-ID: <57344889.1050802@arm.com> References: <1462531568-9799-1-git-send-email-andre.przywara@arm.com> <1462531568-9799-28-git-send-email-andre.przywara@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: Eric Auger , kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org To: Andre Przywara , Christoffer Dall Return-path: Received: from foss.arm.com ([217.140.101.70]:56968 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751868AbcELJKg (ORCPT ); Thu, 12 May 2016 05:10:36 -0400 In-Reply-To: <1462531568-9799-28-git-send-email-andre.przywara@arm.com> Sender: kvm-owner@vger.kernel.org List-ID: On 06/05/16 11:45, Andre Przywara wrote: > The priority register handlers are shared between the v2 and v3 > emulation, so their implementation goes into vgic-mmio.c, to be > easily referenced from the v3 emulation as well later. > There is a corner case when we change the priority of a pending > interrupt which we don't handle at the moment. > > Signed-off-by: Andre Przywara > --- > Changelog v1 .. v2: > - adapt to new MMIO framework > > virt/kvm/arm/vgic/vgic-mmio-v2.c | 2 +- > virt/kvm/arm/vgic/vgic-mmio.c | 39 +++++++++++++++++++++++++++++++++++++++ > virt/kvm/arm/vgic/vgic-mmio.h | 7 +++++++ > 3 files changed, 47 insertions(+), 1 deletion(-) > > diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c > index 054b52d..2e17250 100644 > --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c > +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c > @@ -84,7 +84,7 @@ static const struct vgic_register_region vgic_v2_dist_registers[] = { > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_CLEAR, > vgic_mmio_read_active, vgic_mmio_write_cactive, 1), > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PRI, > - vgic_mmio_read_raz, vgic_mmio_write_wi, 8), > + vgic_mmio_read_priority, vgic_mmio_write_priority, 8), > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET, > vgic_mmio_read_raz, vgic_mmio_write_wi, 8), > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG, > diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c > index dbf683e..d7fe9e6 100644 > --- a/virt/kvm/arm/vgic/vgic-mmio.c > +++ b/virt/kvm/arm/vgic/vgic-mmio.c > @@ -282,6 +282,45 @@ retry: > } > } > > +unsigned long vgic_mmio_read_priority(struct kvm_vcpu *vcpu, > + gpa_t addr, unsigned int len) > +{ > + u32 intid = addr & 0x3ff; > + int i; > + u64 val = 0; > + > + for (i = 0; i < len; i++) { > + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); > + > + val |= (u64)irq->priority << (i * 8); > + } > + > + return val; > +} > + > +/* > + * We currently don't handle changing the priority of an interrupt that > + * is already pending on a VCPU. If there is a need for this, we would > + * need to make this VCPU exit and re-evaluate the priorities, potentially > + * leading to this interrupt getting presented now to the guest (if it has > + * been masked by the priority mask before). > + */ > +void vgic_mmio_write_priority(struct kvm_vcpu *vcpu, > + gpa_t addr, unsigned int len, > + unsigned long val) > +{ > + u32 intid = addr & 0x3ff; > + int i; > + > + for (i = 0; i < len; i++) { > + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); > + > + spin_lock(&irq->irq_lock); > + irq->priority = (val >> (i * 8)) & 0xff; This is wrong. We should only write the number of bits of priority we actually emulate. And given that we use a common framework for v2 and v3, this should probably be 5 bits (32 priorities should be enough for everybody). I'll try and cook something. M. -- Jazz is not dead. It just smells funny... From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Thu, 12 May 2016 10:10:33 +0100 Subject: [PATCH v3 27/55] KVM: arm/arm64: vgic-new: Add PRIORITY registers handlers In-Reply-To: <1462531568-9799-28-git-send-email-andre.przywara@arm.com> References: <1462531568-9799-1-git-send-email-andre.przywara@arm.com> <1462531568-9799-28-git-send-email-andre.przywara@arm.com> Message-ID: <57344889.1050802@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/05/16 11:45, Andre Przywara wrote: > The priority register handlers are shared between the v2 and v3 > emulation, so their implementation goes into vgic-mmio.c, to be > easily referenced from the v3 emulation as well later. > There is a corner case when we change the priority of a pending > interrupt which we don't handle at the moment. > > Signed-off-by: Andre Przywara > --- > Changelog v1 .. v2: > - adapt to new MMIO framework > > virt/kvm/arm/vgic/vgic-mmio-v2.c | 2 +- > virt/kvm/arm/vgic/vgic-mmio.c | 39 +++++++++++++++++++++++++++++++++++++++ > virt/kvm/arm/vgic/vgic-mmio.h | 7 +++++++ > 3 files changed, 47 insertions(+), 1 deletion(-) > > diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c > index 054b52d..2e17250 100644 > --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c > +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c > @@ -84,7 +84,7 @@ static const struct vgic_register_region vgic_v2_dist_registers[] = { > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_CLEAR, > vgic_mmio_read_active, vgic_mmio_write_cactive, 1), > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PRI, > - vgic_mmio_read_raz, vgic_mmio_write_wi, 8), > + vgic_mmio_read_priority, vgic_mmio_write_priority, 8), > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET, > vgic_mmio_read_raz, vgic_mmio_write_wi, 8), > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG, > diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c > index dbf683e..d7fe9e6 100644 > --- a/virt/kvm/arm/vgic/vgic-mmio.c > +++ b/virt/kvm/arm/vgic/vgic-mmio.c > @@ -282,6 +282,45 @@ retry: > } > } > > +unsigned long vgic_mmio_read_priority(struct kvm_vcpu *vcpu, > + gpa_t addr, unsigned int len) > +{ > + u32 intid = addr & 0x3ff; > + int i; > + u64 val = 0; > + > + for (i = 0; i < len; i++) { > + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); > + > + val |= (u64)irq->priority << (i * 8); > + } > + > + return val; > +} > + > +/* > + * We currently don't handle changing the priority of an interrupt that > + * is already pending on a VCPU. If there is a need for this, we would > + * need to make this VCPU exit and re-evaluate the priorities, potentially > + * leading to this interrupt getting presented now to the guest (if it has > + * been masked by the priority mask before). > + */ > +void vgic_mmio_write_priority(struct kvm_vcpu *vcpu, > + gpa_t addr, unsigned int len, > + unsigned long val) > +{ > + u32 intid = addr & 0x3ff; > + int i; > + > + for (i = 0; i < len; i++) { > + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); > + > + spin_lock(&irq->irq_lock); > + irq->priority = (val >> (i * 8)) & 0xff; This is wrong. We should only write the number of bits of priority we actually emulate. And given that we use a common framework for v2 and v3, this should probably be 5 bits (32 priorities should be enough for everybody). I'll try and cook something. M. -- Jazz is not dead. It just smells funny...